Nikon Manual Focus Lens Versions

May 2008

Nikon Pre-AI / Non-AI(originally called Nikon F lenses) introduced in 1959.
Aperture ring marked with red arrow is intact. Will not mount to any of Nikon's Pro Dslr's. Mounting a Pre-AI lens on any of these and you might damage the camera.

Nikon AI' d lenses. This is lenses modified to fit AI cameras. There is two different modifications, one being the classic DIY(do it yourself) modification(to convert a lens to AI'd it's necessary to mill away some of the metal on the aperture selector, marked by red arrow and outlined, this is not necessary on Nikon D40(x) or D60 Dslr's) , the other option is to get a hold of a conversion kit from Nikon. These are no longer being made, and are quite rare to find. Also note that there was not made a conversion kit for all of the Pre-AI lenses.
Lenses that has been converted to AI' d with a Nikon conversion kit look identical to AI lenses, and can usually be identified by - screws instead of + screws. They can also be identified by the serial number on the lens.

Nikon AI* lenses. These are lenses that fall between the Pre-AI and the AI lenses. The lens pictured here is the Reflex-Nikkor 500mm f/8. There is also other AI* lenses, like the PC-Nikkor 35mm f/2.8 and the Medical-Nikkors. What all these AI* lenses have in common is that they don't have the meter coupling prong. Some of these can be mounted to any of the Nikon Dslr cameras on the market, you have to check the manual for your camera to figure out which ones. Some times there are certain serial numbers of lenses that can and can't be mounted. Like the PC-Nikkor 35mm f/2.8

Nikon AI lenses, introduced in
1977. AI(Automatic Aperture Indexing) lenses have a grove milled in the aperture ring (marked by arrow and red outline).
Will mount on 99% of Nikon camera since Nikon F .

Nikon AI-S lenses, introduced in 1982. AI-S(Aperture Indexing Shutter system) AI-S lenses is identical to AI lenses except for a small grove marked by the red arrow. This grove is only used by a few cameras like: Nikon FA,FG, N2020/F501, N2000/F301 and F4. Usually AI-S lenses are more expensive, without any gain in performance. Nikon AF Lenses are still AI-S lenses, but it is uncommon to call a Nikon AF lens AI-S.

Nikon AI-P or P lenses, introduced in 1988.
Nikon AI-S manual focus lenses fitted with a
CPU (CPU marked with red arrow) to allow Matrix metering with early Nikon Dslr's
and film cameras like Nikon D100, F5,
F80/N80, F65/N65
etc.
In total Nikon only made three AI-P lenses., Nikkor 500mm f/4P, Nikkor 45mm f/2.8P and Nikkor 1200-1700/5.6-8P.
Lenses modified with a CPU is also considered a AI-P lens. Lens shown above is a Nikkor-P Auto 600mm f/5.6 P.